The present invention relates to a travel limit detection/control device for a milling machine and, more particularly, to a travel limit detection/control device for a table of a milling machine.
Milling machines are widely utilized to mill various workpieces to obtain planar faces, curved faces, angled portions, gears, holes, grooves, cams, etc. and capable of achieving high yield at high speed through change of cutters. FIG. 1 shows a typical milling machine including a frame 91 mounted on the ground and a table 92 slideably mounted on frame 91. Table 92 is driven by a power device 93 such as an electric motor to move reciprocatingly on frame 91 so that a workpiece placed on table 92 can be milled by cutters mounted on a turret located above table 92. The milling machine further includes left and right activators 95 and 96 and left and right limit switches 97 and 98 for limiting left and right travels of table 92. In practice, leftward and rightward travels of table 92 are set based on the size of the workpiece that is measured beforehand, avoiding useless travels of table 92, enhancing processing efficiency, and saving processing time. However, limit switches 97 and 98 are exposed on table 92 and, thus, liable to be damaged by inadvertent impact. Furthermore, long exterior wires 99 connected to the exposed limit switches 97 and 98 are required. Exposed wires 99 not only adversely affect the appearance of the milling machine but are liable to wear and break, incurring time and costs for repair.
A need exists for a travel limit detection/control device for a milling machine table without utilizing exposed wires and exposed limit switches while allowing reliable detection and control of travel limits of the table through simple operation.